Which reminds me, Trump has a great "say-anything" approach, but one serious challenge he'd need to address is trying to argue principle when he's differentiating his views from Hillary's. The Beest's camp will definitely attack using the kaleidoscope of opinions he's held over the years.
They won't always do it directly. They'll set up pretend-conservative PACs with pretend-conservative names to criticize Trump from the right as a left-wing candidate who is just using conservatives to get elected. Ubama's campaign did this in both his elections.
Trump would need to learn to argue ideas coherently on the key issues in the face of state-run media interview questions. They will specifically try to catch him in contradictions or twist careless turns of phrase--which are his weakness--and contrast them with other things he's said. Their (only) goal is to repeat them enough so that conservatives will lose enthusiasm for him and stay home.
What principles does Trump have to argue?
Trump would need to learn to argue ideas coherently on the key issues in the face of state-run media interview questions.
He's been at it almost 10 months and hasn't been able to do that yet.
Hillary doesn't have any "views", and if she did, you certainly wouldn't be hearing about them this Fall.
What you will hear is "racist, sexist, anti-gay" 24x7, and what you need to beat that is constant, focused, vulgar attacks.
This is not the Agora in Athens. This is 21st Century America, where the Left has mastered rhetoric while the Right feebly responds with "reasoned arguments".
No more losers. GO TRUMP.